Low Glycemic Diet Plus Intervention Reduces Morning Hunger, Increases Satiety

In patients who are obese, a low glycemic diet along with a supervised 12-week aerobic exercise regimen reduces morning hunger and increases satiety throughout the day, according to a study. The GLP-1 secretion was reduced in the low glycemic diet group.…

Karen R. Kelly, PhD, Cleveland Clinic, Ohio, attributed these positive effects to reduced secretion of the glucagon-like peptide-1 (GLP-1), which has been linked in previous research to hunger and satiety.

Changes in GLP-1 secretion correlated with changes in the patients’ hunger (r =.508, P =.04), she reported and added that changes in satiety correlated with decreases in the patients’ body weight (r = -0.744, P =.04).

The Cleveland Clinic study measured 3 naturally occurring peptides previously associated with hunger and energy intake and expenditure (PYY3-36, leptin, and GLP-1) in 17 obese patients aged 65 to 67 years participating in a supervised exercise regimen (1-hour sessions 5 days per week) plus 1 of 2 diets.

Nine patients ate the high glycemic diet (with a glycemic index of 80), while 8 patients were assigned to the low glycemic diet (glycemic index of 40). Over the course of the day, the researchers evaluated the patients’ hunger/satiety, responses to oral glucose stimulation as well as their GLP-P, PYY3-36, and leptin levels.

Both groups experienced similar weight loss (-7.64 +- 1.3 kg) and increased levels of leptin (P <.0001) and PYY3-36 secretion (P =.01).

The only significant difference was GLP-1 secretion (area under the curve, P =.03), which was reduced in the low glycemic diet group. These patients reported less morning hunger and greater satiety throughout the day. In contrast, GLP-1 and hunger/satiety did not change in the high glycemic diet group.

Dr. Kelly said the findings indicate that while exercise-dependent weight loss independent of diet composition normalizes the body’s secretion of PYY3-36 and leptin, it does not seem to mediate hunger/satiety. Instead, the results suggest that GLP-1 may be a more effective target for achieving long-term weight control.

Presented at Obesity 2010: 28th Annual Scientific Meeting of The Obesity Society. [Presentation title: Exercise Combined With a Low Glycemic Diet Enhances GLP-1 Regulation of Appetite in Obese Adults. Abstract 72-OR]